Shock-absorbing handpiece



L. E. EVHJN SHOCK ABSORBING HANDPIECE.

Filed Aug; 25, 1925 Patented Sept, 25,

LEO E. EVSLIN, OF NEW YORK, N. Y.

snooit-an sonisine riiinnrinon.

Application filed Aug'hst 25, 1225. Serial No. 52,372.

This invention relates to dental and surgical implements, and more particularly to that class of tools and implements which employ a. rotating mandrel or spindle, carrying cutting burs, grinding Wheels or like instruments.

The principal object of the invention is to provide a new and improved mounting for the shaft, or shanks of the bur or grinding Wheel member, whereby these instruments will be held with a slightly yielding grip, by virtue of the interposition between. their shanks and the adjacent walls of .a rubber or like resilient cushion which absorbs the shock by reducing the force of impact of the revolving instrument, operating on live tooth structure, bone, etc, thereby reducing the vibration and accompanying heat, pain and disc0m tort to the patient incident to the operation.

l urther, it permits taster worl; without additional discomfort to the patient and rediices the strain and tension of the operators wrist and fingers.

lln hand operating instruments such as chisels, sealers, etc., the yielding of the resilient element between the instrument and the walls of the handle cushions the force applied and thejcutti'ng] or excavating may be done with greater ease, expedition and certainty.

Other objects of the invention will become obvious in the following description of the elements, the combination and'arrangeinent of parts and application of principles, constituting the invention; and the scope of protection contemplated will be indicated. in the appended claims.

lln the accompanying drawing, wherein is illustrated several forms oi? en'ibodiments of the invention lFigure 1 is a side view of a conventional type of right angle hand-piece made in accordance with the invention.

Figure 2 illustrates in detail the elements comprising the l1and-piece head, the cushioned bushing comprising a part of the invention being shown in enlarged section.

Figure 8 is an enlarged view partially in section showing a modification of a handpiece head.

Figure i is a side view of a straight line h and-piece partially in section.

Referring to the drawing in detail, the numeral 1O designates the sheath or hand grip of a right angle hand-piece, having a slip tion out the joint 11, to connect with the usual flexible shaft or other driving means, not shown, and a spindle 12 removably attached to a head 13 to which is also removably secured a nose piece 1 1.

The hand-piece head is provided with an opening to receive the bearing spindle 12 in which is a revolvable driving spindle 15 secured to a bevel gear 16.

Another opening, intersecting the spindle opening at an angle ninety degrees provides space toreceive a bur driving member comprising a gear 17 engageable with the gear 16 and a collar 18 integral With its tubularbody l9.

Screw-threads upon the short tubular eX- te11sion20, of the head 13, provide means for engaging the nose piece 14, the same containing a bored opening 21 receptive of a guide bushing, comprisinga tubular steel bushing 22 having a flangedhead 23, and a resilient outer covering or sleeve2i surrounding the body and ren'iovably held within the opening 21 of the nose piece 14. V y

In an assembled hand-piece, as in Figure 1, the bur driving member, comprising elements 1?, 18 and 19, is introduced into the head 13 and is held in meshedengagement with the driving spindle gear 16 by the nose piece 14-, the flanged head 23 of the resilient bushing being interposed between the nose piece and the lower face of the gear 17.

It will be seen that dental burs or like instruments may be inserted in the hand-piece in the usual wa and there held by means common to hunt pieces of the general type described.

It will also be seen that tions developed in, the hand-piece, or by ac bur in. cutting, will be largely absorbed by the resilient cushioned bushing and not transmitted to the part being operated upon.

Figure represents a modification in the application of a shock absorbing means to certain, types of hand pieces which consists, in addition to the foregoing elements, of a thin walled shell-like casing 25 provided with a slotted end element 26 shaped to partially surround the head member 13 and secured thereon by means of the clamping action between the spindle bearing 1.2 and the head 13.

A thrust bushing 27 has a flange 28 secured within the recess formed in the casing 25 and provides means for maintaininga resilshocks and vibraiently cushioned bushing member having elements 22, 23 and 24, illustrated in the enlarged sectional detail of Figure 2 and previously described.

A straight line hand-piece, shown in'Figare at, is composed of a slip joint unit 30, a sheath 31, and a nose-piece 32 tapered exteriorly and interiorly and integral with the end of the sheath 31. I

lVithin the confines of the Walls of the nosepieee 32 are gripping means, not shown, for rotatably driving a dental-bur or similar instrument.

A sleeve 33 is internally bored and tapered .o conform to the exterior of the nose-piece 32 and is held against rotation by a pin 3a fixed in 'thenose-piece'to slidably engage in a slot 35 formed through the Wall of the sleeve 33.

An opening 36, tormedin the sleeve 83, provides space for the resilient cushioned bush- 'ing elements 22, 23 and 24, as shown in the enlarged section of Figure2 and which provides a practical and e'tlicient means for absorbing shocks and vibrations,

lVhile certain preferred embodiments of tliis deviee have'been shown and described, it will beunderstood that changes in the form,

arrangements, proportions, sizes and details thereof may be made without departing from the scope of the invention as defined in the appended claims. Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is 7 1. In a hand-piece, the combination with a barrel, having head and a rotatable spindle housed inthe head, said head having a cylin drical axial bore in its outer end, of a rubber tube fitting the mentioned bore, and a bushingin said tube having an axial opening to receive a tool carrying shank.

'2. In a hand-piece, the combination with the head thereof, and a rotatable spindle housed in the head, said head having a cylindrical axialbore in its outer end, of an elastic sleeve disposed in the mentioned bore, said sleeve being'receptive of a tool shank to absorb lateral shocks due to the operation of the tool.

In a hand-piece, the combination with the head thereof, and a rotatable spindle housed in the head, said head having an axial bore in its outer end, of an elastic bushing fitting the mentioned bore, said bushing having anaxial'opening to receive a tool carrying shank, and means for confining the bushing within the bore.

t. In a hand-piece, the combination with the head thereof, and a rotatable spindle housed in the head, said head having an axial bore'in. its outer end, of an elastic bushing litting the mentioned bore, and a metal sleeve in said bushing to receive a tool. carrying shank, said bushing being tight titted upon the sleeve.

5. In a hand-piece, the combination with a barrel having a revoluble spindle therein, anda head on said barrel provided with a socket, of a tubular cushion member located in said socket and adapted to receive the shank of aburr or like device in said cushion member, and a sleeve to re-enforcc said cushion member.

6. In a hand-piece, the combination with a barrel, having a head and a rotatable spindle housed in the head, said head having a bore inits outer end, of a flexible sleeve disposed in the mentioned bore, said sleeve being receptive of a tool shank to absorb lateral shocks due to the operation of the tool, and a metal casing enclosed in said sleeve.

7. In a hand-piece, the combination with a barrel having a head and a rotatable spindle housed in the barrel, said head containing a. bore in its outer end, of an elastic bushing in the mentioned bore, said bushing having an axial opening, a metal sleeve fixed in said bushing, said sleeve having a flange and being adapted to receive a tool carrying shank, and means for confining the bushing within the mentioned bore.

In testimony whereof I have signed my name to this application.

LEO E. EVSIAIN. 

